This is part of a series of occasional articles exploring the new terrain of parenting today. By helping you make sense of today’s parenting challenges, questions and concerns, we hope you’ll feel more comfortable, confident and supported in your child-rearing efforts. – The Editors
By Christina Elston
When our 13-year-old started junior high last year, we bought her a cell phone so that we could be in touch in case of an emergency. We warned her: “This is not a toy.”
In Britain, the National Radiological Protection Board (NRPB) would have offered a sterner caution. This past January, the organization – part of the country’s Health Protection Agency – recommended that kids ages 9 to 14 minimize cell-phone use as much as possible, and that children under age 8 not use them at all.
“I don’t think we can put our hands on our hearts and say mobile phones are safe,” NRPB Chairman Sir William Steward said at the time.
But, despite this warning and plenty of discussion in the media about a possible link between cell-phone use and brain tumors, most large-scale studies suggest that cell phones are, indeed, safe.
And what about wireless networks – otherwise known as “wi-fi”? While there isn’t a lot of research available on the health risks of these networks – which allow computer users to access the Internet wirelessly in coffee shops, hotels, airports and other public places as well as at home – studies so far suggest that exposure to wireless networks may carry even less risk than exposure to cell phones.
What We Know
The main concern among those who worry about wireless technology’s effects on our health is the radiofrequency (or “RF”) radiation that cell phones and wireless networks use to carry our communications. These are the same type of waves that bring us radio and television broadcasts, and the same ones your microwave uses to bake your potato.
Thermal Risks? – At high enough levels, RF energy can heat body tissue and cause what the Federal Communications Commission (FCC) calls “thermal effects,” including blindness and sterility. But this level of exposure is more commonly an occupational hazard – for those who work in direct contact with TV or radio antennae – than a risk to the general public.
The FCC measures RF radiation according to the amount that the body absorbs, the “specific absorption rate” (SAR). FCC regulators consider the maximum safe SAR for whole-body exposure to be 4 watts per kilogram of body tissue, and they require mobile-phone manufacturers to demonstrate that the body will not absorb more than 1.6 watts per kilogram from their products. (For more information on your cell phone’s SAR, check out www.fda.gov/cellphones.)
Abiy Desta, a researcher with the U.S. Food and Drug Administration’s Center for Devices and Radiological Health, says that cell phones simply aren’t powerful enough to cause thermal effects on the body. “There is no known risk in cell-phone use,” Desta states.
Cancer Risks? – Though a few studies have suggested possible cancer-causing effects associated with cell-phone use, Desta says these were small and have not been reproduced.
Larger studies also have found no risk, according to John D. Boice, Jr., Sc.D., scientific director of the International Epidemiology Institute and professor of medicine at Vanderbilt University Medical Center in Tennessee. “A rather clear picture is now being developed that there is just no evidence for adverse effects related to the use of cellular phones,” Boice says.
Boice, whose four teenagers use cell phones, was involved in a Danish study, published Feb. 7, 2001, in the Journal of the National Cancer Institute, which followed 420,000 cell-phone users in Denmark from 1982 through 1995 and used the Danish Cancer Registry to determine which of these users developed tumors. The researchers found no evidence that tumors of the brain or salivary gland, leukemia or other cancers were related to cell-phone use.
Several other studies offer basically the same conclusions. They include a Swedish study published in the July 1999 issue of the International Journal of Oncology; and two National Cancer Institute (NCI) studies, one published in the Dec. 20, 2000, issue of the Journal of the American Medical Association and the other in the Jan. 11, 2001, issue of the New England Journal of Medicine. The most recently published study on the subject, in the Aug. 30 issue of the British Journal of Cancer, found no increased risk of a tumor in the nerve connecting the ear to the brain after even 10 years of cell-phone use.
These and other findings have convinced many experts that cell-phone use is safe – even for children.
“My interpretation of the most current literature is that there is no significant risk of adverse effects from cell-phone use in kids,” says Michael Shannon, M.D., chair of the American Academy of Pediatrics’ (AAP) Committee on Environmental Health.
What We Don’t Know
And yet, there are still unknowns. For instance, because all of the research on cell-phone use has examined its effects on adults, we don’t know for certain how it impacts children. In its chapter on electric and magnetic fields, the AAP Environmental Health Handbook, a publication for pediatricians, states that, “the level of energy absorption in children while using cellular telephones is comparable to the level in adults; however, due to the larger number of ions contained in the tissue of children, the specific tissue absorption rate may be higher.”
We also don’t know the impact of very long-term use of cell phones. Cell phones just haven’t been around very long, and, as John Moulder, Ph.D., director of radiation biology at the Medical College of Wisconsin, points out, “things that cause cancer take decades to do it.”
Though it still concluded that cell phones did not increase the risk of cancer, the study from the British Journal of Cancer did find that 10-year cell-phone users who developed tumors were more likely to have them on the side of the head where they held their phones.
Furthermore, we still don’t know much about the effect of exposure to wireless networks. “We don’t know what the exposure levels are in your local coffee shop,” says Moulder. Exposure varies with the number of laptops in use, what those laptops are doing, and proximity to the antenna, he says.
Moulder does point out that wireless network base antennae are much less powerful than the cell-phone transmitters mounted on towers and buildings, and that laptops only transmit intermittently, rather than continuously as cell phones do during a call. So, he says, RF exposure at the coffee shop is likely to be less than during a cell-phone call.
Complicating matters, Moulder says, is the fact that there’s no way to actually prove that something does not cause cancer. Instead, he says, “The world is divided into things that we know cause cancer, and things that might cause cancer.”
Which brings us back to the British health warnings, which are based on what scientists call the “precautionary principle”: Better safe than sorry.
If you’re feeling precautionary, what can you do? Here are some tips for your family:
• Only make cell-phone calls when you’ve got a good signal. Phones with lots of dots reduce their power level (and your SAR) to around 20 percent of maximum. “If you’re seeing only one dot, your phone is probably working very hard, and you’re likely near the maximum SAR,” Moulder says.
• Text message. This keeps the phone away from the head and body, and only exposes you to RF energy while the phone is sending your message.
• Use “ear buds” and hold the phone away from your body during calls. Of course, some health professionals note that this may elevate the risk of hearing damage.
• Avoid “shielding” devices, which are generally marketed and sold online as a way to protect yourself from RF exposure, actually make things worse, Moulder says. The shields decrease the phone’s signal strength, causing the phone to automatically increase both its power output and your RF exposure.
• Keep things in perspective. The AAP’s Shannon suggests viewing the potential risk posed by cell phones and wireless networks in the context of the threats we live with every day.
“You stack them up, and for me, personally, I can’t put cellular phones at the top of my list of concerns,” Shannon says.
Even with cell phones, there are apparently bigger worries than cancer risk. As Howard Cyr, Ph.D., lab leader at the FDA’s Center for Devices and Radiological Health, points out, “There is a risk that’s fairly well established, and that is using cell phones while driving.”
Christina Elston is a regular contributor to United Parenting Publications, specializing in family health issues.
More Health Notes
Beyond the research articles cited in this article, you can find consumer-friendly information on cell phones and radio-frequency exposure on the following government Web sites:
• Cell Phone Facts: Consumer Information on Wireless Phones – www.fda.gov/cellphones – Prepared by the FCC and the FDA, this site explains how cell phones work and offers information on cell-phone safety, continuing research, government standards on radio-frequency exposure, and the radio-frequency absorption rates for particular cell phones.